Hello,

I am new to the Ford trucks. I recently bought an 89 F250 with the 351w I was using the front tank only because I was told the rear tank was leaking. I filled the front tank all the way to the top and got about a quarter mile from the gas station and she quit running. It would sputter when trying to fire up but would only turn over. Towed it home and on the first prime of the pump I got 20lbs of pressure at the rail, without trying to start it I turned the key to off and then primed the lines/rail again and the gage shot up to 42lbs, cranked it over and she fired up and idled for a second or two, then the gage went to 0lbs and the engine died. When leaving for work the next morning I noticed a lot of fuel on the ground coming from the top of the tank. After work tried to start it and it fired up and would idol for apx. 10 seconds, when trying to rev up the engine it fell on its face and died then wouldn't start again. Then I notice more fuel on the ground. I changed the fuel filter and changed the fuel pump relay. (EEC relay is working fine). I checked the inertia switch and it is in the down location. After that I gave up for the night.

Can anyone explain what is going on? Why its not starting? Is the low pressure and/or the high pressure pump bad? Why is there fuel on the ground?

I appreciate your time and responses,
zebraz

 

Sounds like you may be building pressure or vacuum in the fuel tanks. Turn the key on and then off two or three times and then remove the gas caps. Try staring the engine and see if it will run and rev up. The hose from the roll over valve on top of the fuel tank may have been plugged by someone. Or the vented fuel caps may not be letting air into the tanks.

If gas still is running out you need to go under the truck and find out where it is coming from.

Do you hear the pumps run when you turn the key off and on after it dies? Have someone at filler tube with the cap off lessening. Also lessen at the high pressure pump on the frame.

Lets us know what you find out.

 

Hello again, and thank you for the quick reply.

I tried turned the key on and off 3 time and removed both gas caps. No luck. but did notice more fuel leaking from the tank at the same spot. If you lay under gas tank looking up at it with your feet at the rear axle, its coming from the top of the tank dripping off to the left (passenger) side next to the guard that separates the rear drive shaft and the front tank.

I could hear some clicking coming from underneath the truck. Might be the fuel pumps. I did remove the fuel filter and tried to see if any fuel would come out of the line and didnt get a drop when i tuned the key on.

Is it possible that only one pump is bad and causing the other not to run? or both of them go out at once. (both meaning the front tank pump and pump on the frame)



Thanks again!
zebraz

 

You need to have some one listen at the tanks and the frame pump as you turn on the key each time to what pumps are running.

Note that the frame pump and the selected tank pump will only run for one second each time you turn on the key.

We need to know what is working to help you out.

You need to drop the tank to see where the fuel is coming from.
The selector valve may be plugged up as well.

 

Ok. Will both pumps be obvious that they are running? Will they sound like the newer trucks?

 

Yes and yes.

 

Turns out it was a wire loose from the relay plug.

But now I ran into another issue. New battery and new alternator, but my battery light is on inside the cab. My volt gage reads just over the red low mark on the dash. Can you help me with that? FYI. Belt tension is tight.

 

Are you saying it is over charging, if so replace the regulator.
Also you might check the "A" wire and make sure it has battery voltage at the regulator.

 

I'm saying its under charging.Where is the regulator located on my truck?

Once again, I appreciate your quick responses and knowledge.

 

More than likely it goes in at the back of the alternator.

 

I wouldn't trust the in cab voltage gauge very much, mine reads low all the time, but if I check the voltage with a meter at the battery the alternator is working just fine (reads ~14 volts.)

 

When I put the new battery on it started nice and easy. But now its starting really hard. Charging system under no load is 11.31 volts, loaded is 10.94.

 

You have a bad alternator or bad voltage regulator. Under full load (wipers on max, high beams, and fan blower on max) at idle you should see NO LESS then 13.0V.

If it is the regulator, it'll be on the passanager-side inner fender. Kinda under the starter solenoid.

Looks like this:


Edit: I'd change the regulator first, as your supposed to change them anyways when doing a new alternator. If that's not it, then the alt you got was a dud.

 

I just got back from the place I bought my alternator, they tested my new one and they said it was good. Isn't the voltage regulator on the back of the alternator?

 

On older truck's they are externally regulated (NOT on the back of the alt).

On my old '92 7.3 diesel it was externally regulated. I'd check where I said to be sure. If nothing is there, then it's internal.